Zeolites SSZ-26 and SSZ-33 are members of a family of microporous crystalline materials in which the two end members are formed by the stacking of layers in an ABAB. . . sequence or an ABCABC. . . sequence. The framework formed by the ABAB. . . stacking sequence (polymorph A) is of orthorhombic symmetry while the framework formed by the ABCABC. . . stacking sequence (polymorph B) is of monoclinic symmetry. Between these two end member polymorphs, there is a family of materials that can be characterized by a fault probability (p). The fault probabilities of p=0% and p=100% represent the end members polymorph B and polymorph A, respectively. The aluminosilicate zeolite SSZ-26 and the borosilicate zeolite SSZ-33 are members of this family of materials having fault probabilities of about 15% and about 30%, respectively. These zeolites have a three-dimensional pore system containing intersecting 10-and 12-ring pores.
The composition and characterizing X-ray diffraction pattern of zeolite SSZ-26 are disclosed in U.S. Pat. No. 4,910,006, which also describes the preparation of the zeolite using a hexamethyl[4.3.3.0]propellane-8,11-diammonium cation as a structure directing agent.
The composition and characterizing X-ray diffraction pattern of zeolite SSZ-33 are disclosed in U.S. Pat. No. 4,963,337, which also describes the preparation of the zeolite using a tricyclo[5.2.1.02,6]decane quaternary ammonium cation as a structure directing agent.
U.S. Pat. No. 7,648,694 discloses a method for preparing SSZ-26/33 zeolites using a structure directing agent selected from 1,5-bis(N,N-dimethylcyclohexylammonium)pentane dications, 1,4-bis(N-cyclohexylpiperidinium)butane dications, and 1,4-bis(N-cyclopentylpiperidinium)butane dications.
U.S. Pat. No. 7,837,978 discloses a process for preparing SSZ-26 using a structure directing agent comprising a cis-N,N-diethyldecahydroquinolinium cation or a mixture of a cis-N,N-diethyldecahydroquinolinium cation and a trans-N,N-diethyldecahydroquinolinium cation.
U.S. Pat. No. 8,647,601 discloses the synthesis of SSZ-33 using 1,1′-(pentane-1,5-diyl)bis(3-methylcyclohexyl)piperidinium dications as a structure directing agent.
There is significant interest in finding alternative, less expensive structure directing agents for the synthesis of zeolites of SSZ-26/33 family of zeolites.
According to the present disclosure, it has now been found that the relatively simple cations described herein can be effective as structure directing agents in the synthesis of zeolites of the SSZ-26/33 family of zeolites.